1. Field of the Invention
The present invention relates to vehicular child safety seats which are secured to a vehicle seat by a seat belt of a vehicle seat. More specifically, the present invention relates to a structure of a vehicular child safety seat capable of providing enhanced securing stability relative to a vehicle seat and facilitating in-vehicle handling.
2. Description of the Background Art
If a conventional vehicular child safety seat (hereinafter referred to as a child seat) has a mechanism in which a support surface for supporting a child is rotatable, the support surface is rotated with the child seat secured to a vehicle seat. Thus, for the purpose of preventing a backrest of the support surface from interfering the vehicle seat (especially, a backrest of the vehicle seat) when the support surface rotates, the backrest is adapted to incline largely forward. Alternatively, the support surface is designed to provide a prescribed distance between the backrest of the child seat and the backrest of the vehicle seat, taking into account a rotating radius of the backrest of the child seat.
However, the former alternative requires a complicated mechanism. In addition, for rotation of the support surface, the backrest must incline forward. As a result, in-vehicle operation becomes complicated.
The latter alternative is accompanied by a problem that the mounting of the child seat to the vehicle seat may become unstable because of the prescribed distance between the backrests of the child seat and the vehicle seat.
An object of the present invention is to provide a child seat capable of providing enhanced securing stability relative to a vehicle seat and facilitating in-vehicle handling.
The child seat of the present invention has a base portion which is secured to a vehicle seat by a seat belt of the vehicle seat, and a support portion forming a support space for receiving a child and rotatably supported by the base portion. The child seat is further provided with a rotation sliding mechanism including a cam member provided in the support portion and an abutting plate provided in the base portion and abutting the cam member for sliding the support portion in forward and backward directions of the base portion with rotation of the support portion.
Thus, the rotation sliding mechanism causes the support portion to move forward during rotation of the support portion, so that the problem of the interference to the vehicle seat during rotation of the support portion is eliminated. Accordingly, the child seat can be designed such that the position of the support portion is close to the backrest of the vehicle seat. As a result, the child seat can be provided with enhanced securing stability relative to the vehicle seat.
Further, unlike the conventional case, rotation of the support portion can be made without having to incline a part which forms the support portion, e.g., the backrest. Thus, in-vehicle handling of the child seat can be facilitated.
To implement the above described invention in a more preferable manner, the following structure is employed. The rotation sliding mechanism is provided with a guide frame which is provided in the base portion for slidably guiding the supporting portion in upward and backward directions, where the cam member has a rectangular outer surface.
Since the cam has the rectangular outer surface, one of corners of the cam is abutted against the abutting plate as the support portion rotates, whereby the support portion is moved forward with rotation. Further, if the cam is rotated beyond a diagonal line, the support portion is moved backward with rotation.
Accordingly, the support portion can smoothly rotate from the back side to the front side, and vice versa.
Preferably, a bias portion is provided between the base portion and the support portion to apply to the support portion a force toward the back side of the base portion. The provision of the bias portion causes the support portion to be readily rotated by the bias force of the bias portion when the support portion moves from the front side to the back side of the support member.
More preferably, a locking portion is provided between the base portion and the support portion for fixing the position of the support portion relative to the base portion. The provision of the locking portion ensures that the support portion is secured to the base when the child seat is used in a vehicle, whereby a higher level of in-vehicle safety is provided when the child seat is used.
The foregoing and other objects, features, aspects and advantages of the present invention will become more apparent from the following detailed description of the present invention when taken in conjunction with the accompanying drawings.